U.S. Pat. No. 3,463,774 discloses that certain 4,1-benzothiazepines and 5,1-benzothiazocines have useful anti-depressant activity on the central nervous system. We have now surprisingly discovered that a series of new and closely related benzothiazocines and benzothiazonines reduce gastric secretions and are thus useful in the treatment and prevention of gastric ulcers. We have also discovered a new method of preparing such compounds.